import itertools
import click
from pathlib import Path


def pairwise(iterable):
    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
    a, b = itertools.tee(iterable)
    next(b, None)
    return itertools.zip_longest(a, b)


class PathPath(click.Path):
    """A Click path argument that returns a pathlib Path, not a string"""

    def convert(self, value, param, ctx):
        return Path(super().convert(value, param, ctx))